I experience this same problem. Ferritin drops like a rock almost instantly. Joined this forum because I've been searching for answers to my symptoms. Can't stay on TRT for more than a month or two because I end up feeling horrible.Thought I'd share my recent ferritin numbers. No donations or iron supplementation during this period.
1/10/2023 - 150mg Test Cyp Weekly (MWF) - Ferritin 16
3/1/2023 - End of Enclomiphene (No Test) - Ferritin 102
3/30/2023 - 84mg Test Cyp Weekly (daily shots) - Ferritin 26
Crazy how quickly ferritin recovered once testosterone was stopped and then how quickly it dropped back after resuming testosterone. 16 to 102 just by stopping testosterone injections, then 102 to 26 with no change except starting testosterone injections, all within 3 months.